For soil?
Starting plants, I use Farffards seedling mix from the farmers co-op. Another outstanding soil is the Canna Bio living soil, whcih is the most amazing grow medium, I just want to pour it on the living room floor and plant grass seed, it smells so good. I just had a chance to play with it for the first time ever... mmmmm.....
But start your seeds in Seedling Mix El Cheapo and get into the bagged media once your plants are established.